Fix: qnan detection code. Appearently I fooled myself when I wrote this.

Fix: MDLLoader does not reset texture array properly when textures are substituted by plain colors. This caused crashes in ~aiScene or heap corruption.

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@677 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/MDLLoader.cpp

@@ -510,6 +510,8 @@ void MDLImporter::SetupMaterialProperties_3DGS_MDL5_Quake1( )
 		if (is_not_qnan(clr.r))	{
 			delete pScene->mTextures[0];
 			delete[] pScene->mTextures;
+
+			pScene->mTextures = NULL;
 			pScene->mNumTextures = 0;
 		}
 		else	{

code/MDLMaterialLoader.cpp

@@ -101,7 +101,8 @@ aiColor4D MDLImporter::ReplaceTextureWithColor(const aiTexture* pcTexture)
 	{
 		if (*pcTexel != *(pcTexel-1))
 		{
-			pcTexel = NULL;break;
+			pcTexel = NULL;
+			break;
 		}
 		++pcTexel;
 	}
@@ -458,7 +459,10 @@ void MDLImporter::CreateTexture_3DGS_MDL5(const unsigned char* szData,
 			delete[] pc;
 		}
 	}
-	else delete pcNew;
+	else {
+		pcNew->pcData = NULL;
+		delete pcNew;
+	}
 	return;
 }
 
@@ -638,7 +642,9 @@ void MDLImporter::ParseSkinLump_3DGS_MDL7(
 		// opacity like this .... ARRRGGHH!
 		clrTemp.r = pcMatIn->Ambient.a;
 		AI_SWAP4(clrTemp.r);  
-		if (is_not_qnan(clrTexture.r))clrTemp.r *= clrTexture.a;
+		if (is_not_qnan(clrTexture.r)) {
+			clrTemp.r *= clrTexture.a;
+		}
 		pcMatOut->AddProperty<float>(&clrTemp.r,1,AI_MATKEY_OPACITY);
 
 		// read phong power

code/qnan.h

@@ -1,20 +1,60 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (ASSIMP)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2010, ASSIMP Development Team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms, 
+with or without modification, are permitted provided that the following 
+conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the ASSIMP team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the ASSIMP Development Team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
 
 /**  @file  qnan.h
  *   @brief Some utilities for our dealings with qnans.
  *
- *   @note Some loaders use qnans heavily to mark invalid values (and they're
- *     even returned by Gen(Smooth)Normals if normals are undefined for a 
- *     primitive). Their whole usage is wrapped here, so you can easily
- *     fix issues with platforms with a different qnan implementation.
+ *   @note Some loaders use qnans to mark invalid values tempoarily, also
+ *     Assimp explicitly enforces undefined normals to be set to qnan.
+ *     qnan utilities are available in standard libraries (C99 for example)
+ *     but last time I checked compiler coverage was so bad that I decided
+ *     to reinvent the wheel.
  */
 
-#if (!defined AI_QNAN_H_INCLUDED)
+#ifndef AI_QNAN_H_INCLUDED
 #define AI_QNAN_H_INCLUDED
 
 // ---------------------------------------------------------------------------
-/** @brief Data structure for the bit pattern of a 32 Bit 
- *         IEEE 754 floating-point number.
- */
+/** Data structure to represent the bit pattern of a 32 Bit 
+ *         IEEE 754 floating-point number. */
 union _IEEESingle
 {
 	float Float;
@@ -27,37 +67,41 @@ union _IEEESingle
 } ;
 
 // ---------------------------------------------------------------------------
-/** @brief check whether a float is qNaN. 
- *  @param in Input value
- */
-AI_FORCE_INLINE bool is_qnan(float in)
+/** Check whether a given float is qNaN. 
+ *  @param in Input value */
+AI_FORCE_INLINE bool is_qnan(float in)	
 {
-	return (in != in);
+	// the straightforward solution does not work:
+	//   return (in != in);
+	// compiler generates code like this
+	//   load <in> to <register-with-different-width>
+	//   compare <register-with-different-width> against <in>
+
+	// FIXME: Use <float> stuff instead? I think fpclassify needs C99
+	return (reinterpret_cast<_IEEESingle*>(&in)->IEEE.Exp == (1u << 8)-1 &&
+		reinterpret_cast<_IEEESingle*>(&in)->IEEE.Frac);
 }
 
 // ---------------------------------------------------------------------------
-/** @brief check whether a float is NOT qNaN. 
- *  @param in Input value
- */
-AI_FORCE_INLINE bool is_not_qnan(float in)
+/** Check whether a float is NOT qNaN. 
+ *  @param in Input value */
+AI_FORCE_INLINE bool is_not_qnan(float in)	
 {
-	return (in == in);
+	return !is_qnan(in);
 }
 
 // ---------------------------------------------------------------------------
 /** @brief check whether a float is either NaN or (+/-) INF. 
  *
  *  Denorms return false, they're treated like normal values.
- *  @param in Input value
- */
+ *  @param in Input value */
 AI_FORCE_INLINE bool is_special_float(float in)
 {
-	return (((_IEEESingle*)&in)->IEEE.Exp == (1u << 8)-1);
+	return (reinterpret_cast<_IEEESingle*>(&in)->IEEE.Exp == (1u << 8)-1);
 }
 
 // ---------------------------------------------------------------------------
-/** @brief Get a qnan
- */
+/** @brief Get a fresh qnan.  */
 AI_FORCE_INLINE float get_qnan()
 {
 	return std::numeric_limits<float>::quiet_NaN();